Abstract:
The National Park Service (NPS), in conjunction with the Biological Resources Division (BRD) of the U.S. Geological Survey (USGS), has implemented a program to "develop a uniform hierarchical vegetation methodology" at a national level. The program will also create a geographic information system (GIS) database for the parks under its management. The purpose of the data is to document the state of ... vegetation within the NPS service area during the 1990's, thereby providing a baseline study for further analysis at the Regional or Service-wide level. The vegetation units of this map were determined through stereoscopic interpretation of aerial photographs supported by field sampling and ecological analysis. The vegetation boundaries were identified on the photographs by means of the photographic signatures and collateral information on slope, hydrology, geography, and vegetation in accordance with the Standardized National Vegetation Classification System (October 1995). The mapped vegetation reflects conditions that existed during the specific year and season that the aerial photographs were taken (July, 1995). There is an inherent margin of error in the use of aerial photography for vegetation delineation and classification.

The purpose of this spatial data is to provide the National Park Service the necessary tools to manage the natural resources within this park system. Several parks, representing different regions, environmental conditions, and vegetation types, were chosen by BRD to be part of the prototype phase of the program. The initial goal of the prototype phase is to "develop, test, refine, and finalize the standards and protocols" to be used during the production phase of the project. This includes the development of a standardized vegetation classification system for each park and the establishment of photointerpretation, field, and accuracy assessment procedures. Fort Laramie National Historic Site was designated as one of the prototype parks. The monument is located in the high Great Plains. It contains prairie, hill, and riverine environments, with vegetation types that include upland woodland, prairie grassland, riverine woodland, and wetlands.

Fort Laramie National Historic Site was created by the National Park Service on July 16, 1938. The park occupies 833 acres of land on the Laramie River, west of its confluence with the North Platte River in western Wyoming. Bureau of Land Management land south of the park (referred to as Plot 3) and northwest of the park (referred to as Plots 1 and 5) are also within the mapping study area. The park is primarily preserved as an historic site. The fort site was occupied first as a fur trading center, then subsequently as a military outpost. It further served as a way station for trappers, traders, and emigrants on the Oregon Trail. The old fort site, located in the western end of the park, contains a complex of restored buildings and ruins, dating from mid and late 19th century, surrounding a lawn quadrangle. The remainder of the park contains disturbed prairie and floodplains. The park itself lies mainly on the floodplain terrace of the Laramie River, with a portion on the North Platte River floodplain terrace just west of their confluence. A small portion of the northwest corner of the park lies above the terrace. Plot 3 lies directly south of the park, across the Fort Laramie Canal. It is an area of rolling hills. Plots 1 and 5 lie 1/4 mile northwest of the park, also in rolling hills. The park is surrounded by rolling hills that are used for grazing and some agricultural cultivation. The city of Fort Laramie is located 3 miles to the northeast of the park.

The sampling approach used in this mapping effort was typical of small park sampling, where all polygons within the park boundary are sampled. Two levels of field data gathering were conducted in this park; plots and observations. Plots represented the most intensive sampling of the landscape and used TNC's 'Plot Form'. Observations consisted of brief descriptions and were designed to obtain a quick overview of the landscape without spending a large amount of time at each sample site. Observation points used the 'Observation Form' data sheet. Examples of both 'Plot' and 'Observation' forms are included in the companion report by TNC. Initially, plots were used to describe the vegetation of the park. A total of 49 plots were obtained from July through August 1996. These plots were used by TNC to describe the vegetation associations found within the park. These descriptions are in the companion report by TNC. Map Validation A field trip was conducted in July of 1997 to assess the initial mapping effort and to refine map class.

Quality
These data have a combined total accuracy of 82.0% (confidence interval 70% - 100%). Individual class accuracies range from 70% to 100% in both errors of commission and omission.

All data that can be photointerpreted is also digitized. This includes alliance/association classes, surface water, and unvegetated/landuse.

Access Constraints
None

Use Constraints
Any person using the information presented here should fully understand the data collection and compilation procedures, as described in these metadata, before beginning analyses. The burden for determining fitness for use lies entirely with the user. For purposes of publication or dissemination, citations or credit should be given to the U.S. Geological Survey and the National Park Service.